1. Field of the Invention
The present invention relates to a light source apparatus.
2. Description of the Related Art
A color image display apparatus typically includes a color liquid crystal panel having color filters and a backlight apparatus that emits white light onto a back surface of the color liquid crystal panel. A fluorescent lamp such as a cold cathode fluorescent lamp (CCFL) is mainly used as a light source of the backlight apparatus. In recent years, however, light emitting diodes (LEDs), which are superior in terms of power consumption, lifespan, color reproducibility, and environmental load, have come into use as the light source of the backlight apparatus.
A backlight apparatus (an LED backlight apparatus) that uses LEDs as a light source includes a large number of LEDs provided on a plate-shaped substrate, and is therefore capable of irradiating the color liquid crystal panel as a surface light source. However, a characteristic of an LED is that variation occurs in brightness and chromaticity among LEDs of identical types. In other words, individual differences exist among LEDs. Therefore, brightness unevenness and color unevenness occur in a light emitting surface of the LED backlight apparatus.
Japanese Patent Application Publication No. 2009-087772 discloses a technique for suppressing brightness unevenness and color unevenness in a light emitting surface of an LED backlight apparatus by combining a plurality of circuit boards (small light emitting substrates) on which LEDs are mounted.
Incidentally, in another known technique, a reduction in power consumption and an improvement in image contrast are achieved by driving the backlight apparatus in individual regions and reducing the brightness of LEDs that emit light onto regions of a display region of the liquid crystal panel in which dark images are displayed. This technique of controlling the brightness of an LED in accordance with a displayed image is known as local dimming control. In the LED backlight apparatus described in Japanese Patent Application Publication No. 2009-087772, brightness control can be performed on each small light emitting substrate by connecting a control substrate to a connector attached to each small light emitting substrate via a wire harness. Here, a wire harness refers to one or more signal wires.